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If there are 10 people in a room what is the probability that any 2 people have the same birthday?
11.7%. (But when there are 23 people, the odds are 50.7%.) In order for 2 people to have the same birthday, then there can only be 9 different dates out of 365 (actually 37 out of 1461). This is roughly equivalent to 2.53% of possible dates. However, the chance of having matching birthdays to any other birthday is actually much larger, because EACH individual has up to 9 chances out of 365 to match another. The probability is calculated using the product of the series p(n) = 1-(n-1/365), which compares the likelihood of all possible pairs of identical birthdays. The chance that no two share a birthday (including the leap day) can be calculated as the product of the terms n = 1 to 10 of [(1461-(4n+1)/1461]. This should also equate to a likelihood of 88% because the Leap Day is only 1 chance in 1461. (see related link)
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What is the smallest number of people in a room where the probability of two of them having the same birthday is at least 50 percent?
23. The probability that at least two people in a room share a birthday can be expressed more simply, mathematically, as 1 minus the probability that nobody in the room shares a birthday.Imagine a fairly simple example of a room with only three people. The probability that any two share a birthday is :1 - [ 365/365 x 364/365 x 363/365]i.e. 1-P(none of them share a birthday)=1 - [ (365x364x363) / 3653 ]=0.8%Similarly,P(any two share a birthday in a room of 4 people)= 1 - [ 365x364x363x362 / 3654 ] = 1.6%If you keep following that logic eventually you getP(any two share a birthday in a room of 23 people)=1 - [(365x364x...x344x343) / 36523 ] = 51%
What is the probability of 2 or more people in a a group of about 30 having the same birthday?
The probability with 30 people is 0.7063 approx.
What is the probability that no two people have the same birthday out of 55?
Leaving aside leap years, the probability is 0.0137
What is the probability that two people selected at random have the same birthday?
1/365 = 0.00274
What is the largest possible number of people in a room if no two people have a birthday in the same month?
12 because there are 12 months and no one in the room has a birthday in the same month
What is the smallest number of people in a room where the probability of two of them having the same birthday is at least 50 percent?
23. The probability that at least two people in a room share a birthday can be expressed more simply, mathematically, as 1 minus the probability that nobody in the room shares a birthday.Imagine a fairly simple example of a room with only three people. The probability that any two share a birthday is :1 - [ 365/365 x 364/365 x 363/365]i.e. 1-P(none of them share a birthday)=1 - [ (365x364x363) / 3653 ]=0.8%Similarly,P(any two share a birthday in a room of 4 people)= 1 - [ 365x364x363x362 / 3654 ] = 1.6%If you keep following that logic eventually you getP(any two share a birthday in a room of 23 people)=1 - [(365x364x...x344x343) / 36523 ] = 51%
What is the probability of 2 or more people in a a group of about 30 having the same birthday?
The probability with 30 people is 0.7063 approx.
What is the probability that no two people have the same birthday out of 55?
Leaving aside leap years, the probability is 0.0137
What is the probability that two people selected at random have the same birthday?
1/365 = 0.00274
What is the probability of your birthday being the same as mine?
The probability of two people's birthday being the same is actually more likely than many would think. The key thing is to note that it doesn't matter what the first person's birthday is. All we need to work out is the probability that the second person has a birthday on any specific day. This probability is 1/365.25 The probability that they were born on June 10th is 1/365.25. The probability that they were born on February 2nd is 1/365.25 and the probability that they were born on the same day as you is 1/365.25
What is the largest possible number of people in a room if no two people have a birthday in the same month?
12 because there are 12 months and no one in the room has a birthday in the same month
What is the probability that two people will have the same birthday out of 25?
Slightly more than 1 in 2.
On average how many people share the same birthday?
On average, in the entire world about twenty eight thousand people will have the same birthday as one another. In a room full of people, there should be two people who have the same birthday.
What is probability that two people will have the same birthday with the assumption that neither was born on February 29th?
1:30
What is probability that 2 persons sharing same birth date?
The probability that two persons share the same birth date can be calculated using the concept of the birthday paradox. In a group of 23 people, there is a probability of approximately 50% that two individuals share the same birth date. This probability increases as the number of people in the group increases due to the increasing number of possible pairs to compare. The calculation involves considering the complementary probability of no one sharing a birthday and subtracting it from 1 to find the probability of at least one shared birthday.
If 15 strangers are all in a room what is the probability of them all having the same birthday?
To determine the probability of 15 random people all having the same birthday, consider each person one at a time. (This is for the non leap-year case.)The probability of any person having any birthday is 365 in 365, or 1.The probability of any other person having that same birthday is 1 in 365, or 0.00274.The probability, then, of 15 random people having the same birthday is the product of these probabilities, or 0.0027414 times 1, or 1.34x10-36.Note: This answer assumes also that the distribution of birthdays for a large group of people in uniformly random over the 365 days of the year. That is probably not actually true. There are several non-random points of conception, some of which are spring, Valentine's day, and Christmas, depending of culture and religion. That makes the point of birth, nine months later, also be non-uniform, so that can skew the results.
What is the probabililty of at least 2 people same birthday from a group of 12 people?
The probability of at least 2 people sharing a birthday in a group of 12 is approximately 0.891. This is calculated using the complement rule, finding the probability that no one shares a birthday and subtracting it from 1. The result indicates that it is highly likely for at least 2 people to share a birthday in a group of 12.
